Jinsook Kim

© 2015 Elsevier Inc.The breakthrough of induced pluripotent stem cell technology has raised the possibility that patient-specific iPSCs may become a renewable source of autologous cells for cell therapy without the concern of immune rejection. However, the immunogenicity of autologous human iPSC -derived cells is not well understood. Using a humanized mouse model reconstituted with a functional human immune system, we demonstrate that most teratomas formed by autologous integration-free hiPSCs exhibit local infiltration of antigen-specific T cells and associated tissue necrosis, indicating immune rejection of certain hiPSC-derived cells. In this context, autologous hiPSC-derived smooth muscle cells appear to be highly immunogenic, while autologous hiPSC-derived retinal pigment epithelial cells are immune tolerated even in non-ocular locations. This differential immunogenicity is due in part to abnormal expression of immunogenic antigens in hiPSC-derived SMCs, but not in hiPSC-derived RPEs. These findings support the feasibility of developing hiPSC-derived RPEs for treating macular degeneration.

© 2015 Elsevier B.V.This article demonstrates an instrumented mouthguard capable of non-invasively monitoring salivary uric acid levels. The enzyme -modified screen printed electrode system has been integrated onto a mouthguard platform along with anatomically-miniaturized instrumentation electronics featuring a potentiostat, microcontroller, and a Bluetooth Low Energy transceiver. Unlike RFID-based biosensing systems, which require large proximal power sources, the developed platform enables real-time wireless transmission of the sensed information to standard smartphones, laptops, and other consumer electronics for on-demand processing, diagnostics, or storage. The mouthguard biosensor system offers high sensitivity, selectivity, and stability towards uric acid detection in human saliva, covering the concentration ranges for both healthy people and hyperuricemia patients. The new wireless mouthguard biosensor system is able to monitor SUA level in real-time and continuous fashion, and can be readily expanded to an array of sensors for different analytes to enable an attractive wearable monitoring system for diverse health and fitness applications.

© 2015 American Chemical Society. We demonstrate straightforward fabrication of highly sensitive biosensor arrays based on field-effect transistors, using an efficient high-throughput, large-area patterning process. Chemical lift-off lithography is used to construct field-effect transistor arrays with high spatial precision suitable for the fabrication of both micrometer- and nanometer-scale devices. Sol-gel processing is used to deposit ultrathin In 2 O 3 films as semiconducting channel layers. The aqueous sol-gel process produces uniform In 2 O 3 coatings with thicknesses of a few nanometers over large areas through simple spin-coating, and only low-temperature thermal annealing of the coatings is required. The ultrathin In 2 O 3 enables construction of highly sensitive and selective biosensors through immobilization of specific aptamers to the channel surface; the ability to detect subnanomolar concentrations of dopamine is demonstrated.

© 2016 American Chemical Society.High quality WSe2 films have been grown on bilayer graphene with layer-by-layer control of thickness using molecular beam epitaxy. The combination of angle-resolved photoemission, scanning tunneling microscopy/spectroscopy, and optical absorption measurements reveal the atomic and electronic structures evolution and optical response of WSe2/BLG. We observe that a bilayer of WSe2 is a direct bandgap semiconductor, when integrated in a BLG-based heterostructure, thus shifting the direct-indirect band gap crossover to trilayer WSe2. In the monolayer limit, WSe2 shows a spin-splitting of 475 meV in the valence band at the K point, the largest value observed among all the MX2 materials. The exciton binding energy of monolayer-WSe2/BLG is found to be 0.21 eV, a value that is orders of magnitude larger than that of conventional three-dimensional semiconductors, yet small as compared to other two-dimensional transition metal dichalcogennides semiconductors. Finally, our finding regarding the overall modification of the electronic structure by an alkali metal surface electron doping opens a route to further control the electronic properties of TMDCs.